Airfield lighting systems may use incandescent or LED lighting fixtures connected to an alternating current (AC) loop. Isolation transformers are often used to electrically isolate the lighting fixtures from the primary current loop. In general, the primary current loop is spliced in order to install or replace an isolation transformer in the airfield lighting system. An isolation transformer designed for use with higher power lighting fixtures, such as, for example, incandescent fixtures, may not be optimal for use with lower power lighting fixtures such as, for example, LED fixtures.